"The Red Sea islands [Sanafir and Tiran] fall within Saudi territorial waters in light of the new border demarcation agreement between Egypt and Saudi Arabia," the Egyptian government said in a statement.
On Friday, Egyptian Prime Minister Sharif Ismail signed the deal with Saudi officials at the presidential palace in Cairo in the presence of Egyptian President Abdel-Fattah al-Sisi and Saudi King Salman bin Abdul Aziz, the latter of whom is currently visiting Egypt.
The government statement went on to describe the agreement as an "important achievement" that would allow both countries to take full advantage of their "rich natural resources".
It added that the border demarcation deal was the "result of six years of hard work and 11 rounds of meetings", noting that two technical committees had used the latest scientific methods to accurately demarcate the maritime border between the two countries.
"Ratification of this agreement will allow Egypt to take advantage of the exclusive economic zone in the Red Sea and will provide Egypt with exploration opportunities for additional natural resources," the government statement read.
It went on to note that the deal would be brought before Egypt’s parliament -- which is dominated by pro-regime MPs -- for ratification.
The agreement came in for heavy criticism by opposition figures, including many prominent former officials and parliamentarians.
In a joint statement, they asserted their "total rejection" of "all agreements concluded by this illegal regime, including the relinquishment of Egypt’s historical right to territorial waters, land and airspace, along with the management of its airports and wealth and its territorial jurisdiction and national sovereignty."
The statement was signed by former MP Tharwat Nafi; Saif Abdul Fattah, a former adviser to ex-President Mohamed Morsi (who was ousted in a 2013 military coup); journalist Abdul Rahman Yousef; former MP Gamal Heshmat; former MP Hatem Azzam; former government minister Amr Darrag; Tariq al-Zumr, head of the Building and Development Party; Ayman Nour, a former presidential candidate; Ihab Shiha, head of the Asala Party; Yahiya Hamid, former assistant to ousted President Morsi; and Muhammad Mahsoub, a former government minister.
Tiran Island (80 square kilometers) lies at the entrance of the Strait of Tiran, which separates the Gulf of Aqaba from the Red Sea only six kilometers from the Sinai coast. Sanafir Island (33 square kilometers) is located to the east of Tiran Island.